Insect pests of food.

  • Great Britain. Ministry of Food.
Date:
1943]
Catalogue details

Licence: Public Domain Mark

Credit: Insect pests of food. Source: Wellcome Collection.

    38/160 (page 196)
    Ephestia elutella (Hbn.) (Figs. 54-55, 57). Figs. 55-58. (55) Spiracle and Kappa group of prothorax of Ephestia elutella (Hbn.). (56) Same of E. sertcarium (Scott). (57) Ventro-mesal view of right mandible of E£. elutella. (58) Same of E. sericarium. Mature Larva.—Length, 10-15 mm.; breadth, 1-0-1:5 mm. » Identical with EL. sericarium except as follows: (1) mandible (fig. 57) with lateral margin of outer or third tooth forming part of outer ventral margin of mandible; (2) prothorax with diameter of spiracular opening distinctly less than distance between Kappa setae (fig. 55); (3) spiracle of eighth abdominal segment of mature or nearly mature arvae (fig. 54) not more than two-thirds as broad as membranous area enclosed by sclerotised ring around base of seta rho; (4) eighth abdominal segment with nu anterior and slightly mesal to pi, whereas in E. sericarvum the fully grown larva has nu either directly anterior or antero-lateral to pi, nu being mesal to pi only occasionally in the earlier instars of the latter species ; and (5) nu of 3-6 always antero-lateral to pi, whereas in fully grown larvae of E. sericartum nu is directly anterior or even antero-lateral to pi. In many specimens of EL. elutella theta is present on either the right or left side of the eighth abdominal segment, and in a few specimens it is present on both sides. Intermediate instars of E. elutella cannot be easily dis- tinguished from those of E. sericariuwm without examining the mandibles. PYRALINAE. The larvae of this subfamily are very nearly related to those of the PHYCITINAE, and Fracker (1915) and other writers have been unable to distinguish them from the