Insect mitochondrial genomics 3: the complete mitochondrial genome sequences of representatives from two neuropteroid orders: a dobsonfly (order Megaloptera) and a giant lacewing and an owlfly (order Neuroptera)

We describe the complete mitochondrial genomes from representatives of two orders of the Neuropterida: a dobsonfly, Corydalus cornutus (Megaloptera: Corydalidae, GenBank Accession No. FJ171323), a giant lacewing Polystoechotes punctatus (Neuroptera: Polystoechotidae, FJ171325), and an owlfly, Ascaloptynx appendiculatus (Neuroptera: Ascalaphidae, FJ171324). The dobsonfly sequence is 15 687 base pairs with a major noncoding (A+T rich) region of approximately 967 bp. The gene content and organization of the dobsonfly is identical to that of most insects. The giant lacewing sequence is 16 036 bp with a major noncoding region of about 1123 bp, while the owlfly sequence is 15 877 bp with a major noncoding region of about 1066 bp. The two Neuroptera sequences include a transposition of two tRNA genes, tRNATrp and tRNACys. These tRNA genes are coded on opposite strands and overlap by seven residues in the standard insect mitochondrial gene arrangement. Thus, the transposition required a duplication of at least the region of overlap. It is likely that the transposition occurred by a duplication of both genes followed by deletion of one copy of each gene. Examination of this region in two other neuropteroid species, a snakefly, Agulla sp. (Raphidioptera: Raphidiidae), and an antlion, Myrmeleon immaculatus (Neuroptera: Myrmeleontidae), shows that the rearrangement is widespread in the order Neuroptera but not present in either of the other two orders of Neuropterida.

DIPALTA SERPENTINA OSTEN SACKEN (DIPTERA: BOMBYLIIDAE) AS A PREDATOR ON PUPAE OF THE ANTLION MYRMELEON IMMACULATUS DEGEER (NEUROPTERA: MYRMELEONTIDAE) IN CALIFORNIA

The first record of Dipalta serpentina Osten Sacken, 1877, preying on larvae of Myrmeleon immaculatus DeGeer, 1773, was by Smith (1934: 136-137), who stated that the fly larvae were “parasitic” on the antlion larvae. Cole and Schlinger (1969: 251) stated that the fly larva of this species “…is parasitic on the larvae of Myrmeleontidae.”Although the fly larvae may prey upon the larvae of the antlion, we have established that they definitely prey upon the antlion pupae (Fig. 1). Judging from the emergence dates (early September 1988) of the flies, each had preyed upon an antlion pupa within its cocoon. Each antlion cocoon had one hole in it. An examination of the contents of each antlion cocoon revealed the cast skin of the antlion larva and the empty, clear skin of the antlion pupa. The pupal skins were not split open, which they would have been if the adult antlion had emerged. They were shrivelled, and looked much as if the contents had been sucked out.