Moth, diamondback

An example of a larval parasitoid that responds to the host sex pheromone is seen with Cotesiaplutellae (Braconidae), also a parasitoid of the diamondback moth. These insects were attracted equally to the pheromone blend (31,32,33, see above), the acetate 32, or aldehyde 31 components [80]. This larval parasitoid, however, was also strongly attracted to host frass volatiles, in particular, dipropyl disulfide 34, dimethyl disulfide 35, allyl isothiocyanate 36, and dimethyl trisulfide 37. In contrast, the egg parasitoid Trichogramma chilonis was only weakly attracted to 36. In both, T. chilonis and C. plutellae, plant volatiles, in particular (3Z)-hex-3-en-l-yl acetate 38, significantly enhanced attraction by the pheromone [80]. 

Tabashnik, B.E. and N.L. Cushing. 1989. Quantitative genetic analysis of insecticide resistance variation in fenvalerate tolerance in a diamondback moth (Lepidoptera Plutellidae) population. Jour. Econ. Entomol. 82 5-10. 

Diamondback moth (Plutella xylostella) Legume pod borer (Maruca vitrata)... 

Mahar AN, Jan ND, Mahar AQ, Mahar GM, Hullio MH, Lajar AG. Efficacy of entomopathogenic bacterium Photorhabdus luminescens and its metabolites against diamondback moth Plutella xylostella larvae on Chinese cabbage and artificial diet. Pak J Nematol. 2008 26 69-82. 

Insecticides Vetch aphid (Megoura viciae) bollworm (Helicoverpa zea) army worm (Spodoptera littoralis) diamondback moth (Plutella xylostella) mustard beetle (Phaedon cochleariae) corn rootworm (Diabrotica undecimpunctata) whitefly Bemisia tabaci) red spider mite (Tetranychus urticae). 

Insects have evolved resistance to Bt toxins in the laboratory, yet only one crop pest, the diamondback moth (Plutella xylostella), has evolved resistance to Bt toxins under open field conditions (Tabashnik et al. 2003). But this resistance was not caused by Bt crops, rather it occurred in response to repeated foliar sprays of Bt toxins to control this pest on conventional (non-GE) vegetable crops (Tabashnik 1994). Based partly on the experience with diamondback moth and because Bt crops cause season-long exposure of target insects to Bt toxins, some scientists predicted that pest resistance to Bt crops would occur in a few years. 

Other pheromones prepared using CM include 11 -tetradeceny 1 acetate (Omnivorous Leafroller), 8,10-dodecadienol (Codling Moth), 9-tetradecenyl formate (Diamondback Moth),47 9,11-hexadec-adienal (Pecan Nut Casebearer),48 and 4-tridecenyl acetate (Tomato Pinworm)49... 

Diamondback Moth Java Salt-marsh Mosquitoes Fla. 

Essential oils from laurel were evaluated for fumigant toxicity against all developmental stages of the confused flour beetle (Tribolium confusum). GC-MS analysis showed that 1,8-cineole was the major component of the essential oils. The vapours of laurel essential oil were toxic to all the stages of T. confusum (Isikber et al., 2006). Repellency and toxicity of essential oil from L. nobilis (Lauraceae) against the rust-red flour beetle T. castaneum Herbst) were also reported by Andronikashvili and Reichmuth (2003). The toxicity of ethanol extracts from L. nobilis on the large diamondback moth, Plutella xylos-tella, was 55% (Erturk et al., 2004). 

Sphecid wasp Philanthus spp.) male territory marker, female attractant Reduced attraction of bark beetle (Pityogenes bidentatus) by pheromones diamondback moth Plutella xylostella) attractant Colorado potato beetle Leptinotarsa decemlineata) attractant Sphinx moth Manduca sexto) stimulated diamondback moth Plutella xylostella) attractant stimulates female polyphemus moth Anthera polyphemus male attractant release (oak leaf needed for mating)... 

Colorado potato beetle Leptinotarsa decemlineata) attractant Reduced attraction of bark beede Pityogenes bidentalus) by pheromones diamondback moth Plutella xylostella) attractant... 

Ryania is made from the ground roots of the tropical shrub Ryania speciosa. The active principle of ryania is the alkaloid ryanodine (C25H35NOu). Ryania is used for controlling aphids, cabbage loopers, Colorado potato beetles, diamondback moths, cucumber beetles, leafhoppers, corn earworms, European corn borers, codling moths, citrus thrips, and so on. Its oral LD30 in rats is 1200 mg/kg so it is practically nontoxic to mammals. 

Tolfenpyrad is the only insecticide of this class. It is active against diamondback moths and aphids on cole and cucurbit crops. Its oral LD30 in rats is >100 mg/kg. 

Cartap hydrochloride is a broad-spectrum insecticide used for control of coleopterous, lepidopterous, and sucking insects, especially Colorado potato beetles, diamondback moths, rice stem borers, and thrips on rice and vegetables. Its oral LD30 in rats is 345 mg/kg. 

Resistance genes can be dominant, recessive, incompletely dominant, or incompletely recessive. Resistance to carbamates and organophosphates is usually dominant or incompletely dominant. Resistance to DDT, Bt, and spinosyns is usually recessive. Resistance to dieldrin is usually incompletely dominant. Resistance to pyrethroids is usually incompletely recessive. As shown in Figure 10.1 and 10.2, diamondback moth resistance to per-methrin was inherited as an incompletely recessive, autosomal factor, whereas resistance to methomyl was inherited as an incompletely dominant, autosomal factor. In cases of monofactorial inheritance of resistance to insecticides, the degree of dominance (D) in the progeny can be calculated, as described by Stone (1968), as follows ... 

Figure 10.1 Probit regression lines for permethrin against susceptible (S) and resistant (R) diamondback moths and their F, progeny. (From Yu, S.J., /. Econ. Entomol, 86, 680, 1993. With permission.)...

Reduced binding of toxin is a primary mechanism of insect resistance to Cry proteins (Ferre and Van Rie, 2002). Resistance of the Indian meal moth to Bt was due to a 50-fold reduction in affinity of the membrane receptor (from brush borer membrane vesicles of larval midguts) for 5-endotoxin. In pinkbollworms, Bt resistance is associated with reduced binding of CrylAb to the brush borer membrane vesicle. Similarly, CrylAc resistance in diamondback moths was demonstrated to be due to dramatically reduced target binding. 

Yu and Nguyen (1996) showed that selection of a strain of diamondback moth (Plu-tella xylostella) with permethrin for 21 generations resulted in over 600-fold resistance to permethrin in this strain. The resistant strain was also cross-resistant to all pyrethroids tested, including bifenthrin, fenvalerate, esfenvalerate, A.-cyhalothrin, fluvalinate, and tral-omethrin. However, it remained susceptible to organophosphate, carbamate, cyclodiene, neonicotinoid, avermectin, and microbial insecticides tested. Biochemical studies indicated that pyrethroid resistance observed in this strain was most likely due to decreased target site sensitivity. 

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