Na+/K+-ATPase resistance and cardenolide sequestration: basal adaptations to host plant toxins in the milkweed bugs (Hemiptera: Lygaeidae: Lygaeinae).

Milkweed butterfly resistance to plant toxins is linked to sequestration, not coping with a toxic diet.

Insect resistance to plant toxins is widely assumed to have evolved in response to using defended plants as a dietary resource. We tested this hypothesis in the milkweed butterflies (Danaini) which have progressively evolved higher levels of resistance to cardenolide toxins based on amino acid substitutions of their cellular sodium-potassium pump (Na(+)/K(+)-ATPase). Using chemical, physiologic...

Two new endemic species of Lygaeinae from Baja California, Mexico (Hemiptera: Heteroptera: Lygaeidae) .

Two new species of Lygaeinae endemic to the Peninsula of Baja California, Mexico, are described. Dalmochrimnus insularis sp. nov. endemic to San Ildefonso Island in the Gulf of California and Melacoryphus lagunensis sp. nov. endemic to the Reserve area of Sierra La Laguna in the South of the Peninsula. A discussion about their relationships within their genera and their endemic status is also p...

Development of Resistance in Southern Chinch Bugs (hemiptera: Lygaeidae) to the Insecticide Bifenthrin

Buffalograss germplasm resistance to Blissus occiduus (Hemiptera: Lygaeidae).

Plant germplasm collections may offer genetic variability useful in identifying insect resistance. The goal of this project was to evaluate buffalograss genotypes [Buchloë dactyloides (Nutt.) Engelm.] for resistance to the chinch bug, Blissus occiduus Barber (Hemiptera: Lygaeidae), and to relate resistance to ploidy level, chinch bug number, and pubescence. Forty-eight buffalograss genotypes fr...

Community-wide convergent evolution in insect adaptation to toxic cardenolides by substitutions in the Na,K-ATPase.

The extent of convergent molecular evolution is largely unknown, yet is critical to understanding the genetics of adaptation. Target site insensitivity to cardenolides is a prime candidate for studying molecular convergence because herbivores in six orders of insects have specialized on these plant poisons, which gain their toxicity by blocking an essential transmembrane carrier, the sodium pum...