Journal of Economic Entomology (1994) 87, 350-355

John D. Vandenberg (1994)
Chalkbrood susceptibility among larvae of the alfalfa leafcutting bee (Hymenoptera: Megachilidae) reared on different diets
Journal of Economic Entomology 87 (2), 350-355
Abstract: Bioassays were conducted to determine effects of diet on chalkbrood, a devastating mycosis of larvae of the alfalfa leafcutting bee, Megachile rotundata (F.). Bees reared in the laboratory on four sterilized diets were assayed for chalkbrood susceptibility, bee development, and survival. Bees reared on a pollen + pollen substitute diet had an LC₅₀ of 138 spores per larva, the shortest time to death, the smallest cadaver size, and the most frequent sporulation. Uninfected larvae developed into normal adults. Bees reared on a pollen + sugars diet had the lowest LC₅₀ (79 spores per larva), the longest time to death, and the lowest sporulation rate. On this diet, the development and survival of uninfected larvae were delayed, and only a few small adults emerged. Bees reared on a pollen + sugars diet with a higher pollen concentration had the highest LC₅₀ (1,549 spores per larva). These bees also had delayed development and reduced survival to the adult stage, but adults were of normal size. Bees reared on sterilized natural provisions had an intermediate LC₅₀ (219 spores per larva), time to death, and sporulation rate, and the largest cadaver size. Development and survival rates for bees reared on this diet were similar to those obtained with bees reared on the pollen + pollen substitute diet, but adults were much larger than those reared on any other diet. Thus, diet factors that promote bee survival and growth are different from those that determine chalkbrood susceptibility.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): John D. Vandenberg

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
resistance/tolerance/defence of host

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ascosphaera aggregata