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Key to Orders and Groups of Pests
1. Body and antennae unsegmented, contractile, slimy; entire lower surface modified as a sort of gliding foot; breathe through single, closable opening on right side of body (Fig. 2A, B) Slugs and Snails.
1.' Body and appendages segmented (3A, B), or if apparently not segmented, then specimens either permanently attached to plants (scales, Fig. 4A, B and whiteflies, Fig 5A, B) or less than 1 mm long (mites, Fig. 6A,B)......2
2. Some combination of the following: wings; three or four pairs of segmented legs; a pair of large compound eyes; a pair of well-developed antennae; body larger, darker and/or harder than that of the immature. (Adult and immatures of mites, aphids, mealybugs, and scales are very similar except for size and reproductive maturity and can be difficult to distinguish) Adults.
2.' No wings; some of the following present or absent: segmented thoracic legs; fleshy abdominal prolegs; eyes; antennae; body larviform (caterpillar, grub, or maggot) or at least smaller, paler, and softer than adult.... Immatures.
Key to adults
1. Specimen permanently attached to leaves or stems, may be hidden under shell or wax secreted by specimen (figs. 4a to 5b.......Scales and immature whiteflies
1'. Specimen mobile, not permanently attached to vegetation.......2
2. Body unsegmented, usually less than 1 mm long; 4 pairs of segmented thoracic legs; wings, compound eyes, and antennae always absent (fig. 6a,b)........Mites.
3. With 1 pair of transparent front wings; hind wings reduced to knob-like halters (7a, b)..Flies.
3.' With 2 pairs of wings or none, front wings may be shell-like, hiding the hind wings.....4
4. Body densely covered with scales and hairs; mouthparts in form of slender, unsegmented tube that is coiled and concealed under head (Fig.8....Moth and Butterflies.
4.' Scales and hairs, if present, sparse and not concealing body surface; mouthparts different....5
5. Front wings in form of a hard or leathery shell meeting at midline but not overlapping, covering the transparent folded hind wings; mouthparts of chewing type, mandibles on head or at tip of unsegmented snout (Fig. 9A to C)......Beetles.
5.' Front wings, if present, either transparent, flexible, or overlapping when closed; mouthparts a segmented beak or cone for piercing and sucking.....6
6. Tiny, slender insects more than twice as long as wide, usually 1 to 2 mm long; wings folded flat on back when closed, overlapping, much narrower than width of body, each bearing a long fringe of marginal hairs (Fig. 10).....Thrips.
6.' Not fitting this description....7
7. Mouthparts a segmented, hinged beak attached to underside of head anterior to eyes (Fig. 11); antenna of four or five distinct segments; front wings folded flat on back, usually (except lace bugs) leathery at base and membranous toward tips, tips overlapping......Bugs
7.' Mouthparts a short beak attached to head under eyes or even between front legs; antennae and wings variable (Fig. 12)....... 8
8. Antennae distinct, segmented, arising from head in front of eyes; insects crawl or fly but don't jump ........ 9
8.' Antennae slender, hairlike, arising from knobs beneath eyes; hind legs long, spiny, adapted for jumping; alert, active insects (Fig. 13) Leafhoppers.
9. A pair of tubelike cornicles on abdomen (Fig. 14) Aphids.
9.' Cornicles absent........10
10. Fully winged, tiny, whitish, active insects with large eyes; found on undersides of leaves among their immobile immatures; fly in spiral pattern when disturbed (Fig. 15) ......Whiteflies.
10.' Wingless, slow-moving, oval insects; body pinkish or grayish under a coat of powdery white wax, often with filaments and tufts of hairlike wax; usually concealed on various parts of plants (Fig. 16) .... Mealybugs.
Key to Immatures
1. Becoming permanently attached to leaves or stems, may be hidden under shell or wax secreted by specimen (Figs. 17A, B, 18A, B) .....Scales and Whiteflies.
1.' Mobile, or capable of crawling when prodded..... 2
2. Lack of legs......3
2.' Possesses legs of some sort .......5
3. Headless, with a pair of retractable mouth hooks, a maggot (Fig 19) .....most Fly maggots.
3.' Has a distinct head capsule (Fig. 20, 21) ......4
4. Slender maggot with shiny black head capsule, found in decaying plant tissues and in fungi (Fig. 20)........ Darkwinged fungus gnat.
4.' Stout-bodied grub with orange or brown head capsule, in soil around roots or boring in healthy plant tissue (Fig 21)...... Weevils and other Beetles.
5. Tiny, body unsegmented, less than 0.5 mm long; 3 or 4 pairs of segmented legs present; eyes and antennae always absent (Fig. 22) ...... Mites
5.' Body segmented, usually longer than 0.5 mm; only 3 pairs of segmented legs; eyes and antennae usually present but may be small or obscure ..... 6
6. Immature a caterpillar or grub, with chewing mouthparts; looking very different from, and not found with, the adult. (Fig. 23A to D) ......... 7.
6.' Immature a nymph with a beak or cone-shaped mouthparts: similar to, and often found in groups with adults.......8
7. Immatures with 3 or 4 pairs of fleshy abdominal prolegs and 1 pair of anal prolegs; some species can spin silk, which they use to tie foliage together, line burrows and spin cocoons (Fig. 23A, B) ..... Caterpillars.
7.' Immatures lacking prolegs; cannot spin silk (fig.23 C, D).... White grubs, Wireworms, other Beetles
8. Mouthparts a segmented, hinged beak attached to underside of head anterior to eyes; antennae of 4 distinct segments; compound eyes well developed; stout-bodied, slender-legged, usually active and solitary nymphs (except lace bugs, which are spiny) (Fig. 24A to D) .... Bugs.
8.' Mouthparts a short beak attached to underside of head beneath eyes or between front legs; antennae and eyes variable; body form variable (Fig 25) ...... 9
9. Active, alert insects, solitary on foliage and stems; hind legs long, spiny, can jump; antennae hairlike, arising from head underneath eyes and above beak (Fig. 25A) Leafhoppers.
9.' Less active, often found in groups or concealed; hind legs not adapted for jumping; antennae arising from head in front of eyes ......10
10. Possessing a pair of tubelike cornicles on abdomen; usually found in clusters or colonies on leaves, new shoots, nymphs and adults together (Fig 25B) ....... Aphids.
10.' Lacking cornicles ....... 11
11. Slender insects, more than twice as long as wide; usually pale yellow or red, lacking a coating of powdery or filamentous wax; eyes visible; mouthparts concealed in a cone on part of head (Fig. 25C) ..... Thrips.
11.' Oval or rounded insects, less than twice as wide as long; body pinkish or grayish beneath a coating of powdery or filamentous wax; eyes lacking; mouthparts a short beak between front legs (Fig. 25D) ..... Mealybugs.
Key to Blossom and Leaf Feeders
1. Body and antennae unsegmented, contractile, slimy, legless; entire ventral surface modified as a sort of gliding foot; breathe through single, closable opening on right side of body (Fig. 26A, B) ....... Slugs and Snails.
1.' Body and appendages segmented, or if apparently not segmented. then specimens either attached to plants or less than I mm long ..... 2
2. Specimens attached to plant, rarely if ever moving (Fig. 27A to D)....... Scales and immature Whiteflies.
2.' Specimens readily mobile.......3
3. Tiny, 1mm or less long; 3 or 4 pairs of segmented thoracic legs; antennae, compound eyes, and wings always absent; body unsegmented. (Fig. 28A, B) ...... Mites.
3.' Usually larger; 3 pairs of segmented thoracic legs; antennae, compound eyes, and wings (adults) usually present although they may be reduced or hidden; body segmented ....... 4
4. Body elongate, soft; head capsule smooth and rounded, hard; eyes and antennae reduced; 3 pairs of thoracic legs plus1 or more pairs of fleshy abdominal prolegs and 1 pair of fleshy anal prolegs (Fig.29) ...... Caterpillars.
4.' Not a caterpillar, abdominal and anal prolegs absent ...... 5
5. Mouthparts are chewing mandibles; body hard; front wings not overlapping, meeting at midline of body, modified into a shell that covers the transparent, folded hind wings; antennae may be elbowed, clubbed, or otherwise modified. (Fig. 30) ....... Beetles.
5.' Mouthparts beaklike or conelike, adapted for piercing and sucking; body leathery or soft; front wings not like a shell, may partly or completely overlap at rest; antennae (except leafhoppers) a simple, straight series of segments......6
6. Mouthparts an elongate three or four-segmented beak that arises in front of eyes on underside of head (Fig.31A); large compound eyes always present; antennae of 4 or 5 distinct segments; front wings of 2 textures, leathery near base and membranous at tips, tips overlapping. (Fig. 31B) bugs.
6.' Mouthparts a beak or cone, arising beneath eyes or (apparently) between first pair of legs (Fig. 32); eyes and antennae variable; front wing of uniform texture..... 7
7. Slender insects, more than twice as long as wide ..... 8
7.' Oval or rounded insects, less than twice as long as wide ..... 9
8. Tiny yellow, brown or black insects, 1 to 2 mm long; antennae long, projecting from front of head; hind legs short, not modified for jumping; front wings (if present lying flat on back when closed, completely overlapping, each wing with a fringe of long hairs on its margins. (Fig. 33) ...... Thrips.
8.' Usually larger than 1 to 2 mm when mature; variously colored and patterned, often green; hind legs long, modified for jumping; antennae short, hairlike, arising under eyes; front wings not lying flat on back or overlapping when closed, lacking fringe (Fig. 34) ......Leafhoppers.
9. With a pair of tubelike cornicles on abdomen; large compound eyes present; legs long and slender; body variously colored and patterned (Fig. 35) ...... Aphids.
9.' Cornicles and compound eyes absent; legs short, not slender; body pinkish or grayish; often covered with a white, waxy bloom (Fig. 36) ........ Mealybugs.
Key to Stem Borers
1. With 3 pairs of short, segmented thoracic legs, plus 1 or more pairs of fleshy abdominal prolegs and 1 pair of fleshy anal prolegs. (Fig. 37)...... Caterpillars.
1.' Abdominal and anal prolegs absent .....2
2. A distinct, hard, pigmented head capsule present, mouthparts are chewing mandibles ...... 3
2.' No distinct head capsule, mouthparts are pair of retractile, downward curving hooks (Fig. 38) ......... Maggots.
3. Head capsule shiny black; body slender, smooth, soft, white; thoracic legs absent. (Fig. 39) ...... Darkwinged fungus gnats.
3.' Head capsule orange to brown; body variable; thoracic legs may be present (Fig. 40A and B) ....Beetles.
Key to Root Feeders
1. Tiny, slow moving, 1 mm or less long; 3 or 4 pairs of segmented thoracic legs; head and mouthparts cone shaped, eyes and antennae absent; body bulbous, unsegmented, with scattered long hairs; found in decaying or moldy vegetation (Fig. 41 ) ...... Mites.
1.' Larger; 3 pairs of segmented thoracic legs or all legs absent; body segmented; caterpillars, grubs, and maggots .......2
2. A distinct head present; mouthparts are chewing mandibles or a sucking beak ..... 3
2.' No head capsule; mouthparts are a pair of retractile, downward curving hooks (Fig. 42) ...... Maggots.
3. All legs present ...... 4
3.' Some legs present ..... 5
4. Head capsule shiny black; body slender (Fig. 39) ..... Darkwinged fungus gnats.
4.' Head capsule orange to brown; body usually stout (Fig. 40A, 43) ..... Weevils, Leaf beetles
5. With three pairs of segmented thoracic legs, plus four pairs of fleshy abdominal prolegs and one pair of fleshy anal prolegs (Fig. 37)..... Caterpillars.
5.' Prolegs absent........ 6
6. Head capsule distinct from body; mouthparts are chewing mandibles; body more than twice as long as wide; white, yellow, or orange to brown in color; no wax (Fig. 44A and B) ..... White grubs and Wireworms.
6.' Head not distinct from body; mouthparts slender, short beak; body oval or rounded, usually less than twice as long as wide; pale pink or gray under a coating of powdery wax (Fig. 45) ..... Mealybugs.