Lygaeus turcicus

False Milkweed Bug

Lygaeus turcicus, a Milkweed Plant Bug




Family: Lygaeidae

Subfamily: Lygaeinae

Length: 10-12 mm


A funny thing happened to Lygaeus turcicus on its way into the literature. Nineteenth century authors noted its similarity to the Small Milkweed Bug, Lygaeus kalmii, and reported that both species fed and bred on milkweeds.

At least one author stated his opinion that the two names actually referred to the same species.

In 1983, researcher James A. Slater began to wonder why he rarely saw the species Lygaeus turcicus despite looking for them on milkweed plants. He wondered, for example, if his Connecticut home was too far north for the species, or if Lygaeus kalmii was simply out-competing Lygaeus turcicus. He searched the literature for information on the life history of L. turcicus, but was able to find little.

Finally, Slater received some fan mail from a Missouri reverend, praising Slater's recent book How to Know the True Bugs. The reverend had been compiling host plant records for Seed Bugs, and he sent Slater a few sample pages from his self-made guide. One such page was for L. turcicus, and stated that almost all collections were from a sunflower species, Heliopsis helianthoides, or a related plant, and added that eggs and nymphs were found on H. helianthoides and not just adults. Slater's correspondent had collected L. turcicus on a sunflower species more than thirty times.

Shortly thereafter A. G. Wheeler, Jr. also wrote Slater, and he too wanted to talk about L. turcicus (which had had little firm information in Slater's book). Wheeler had collected L. turcicus adults and nymphs from H. helianthoides in Randolph County, West Virginia.

With the help of his two informants, Slater soon was able to raise L. turcicus broods in the laboratory on a diet of sunflower seeds. He found that the species also was capable of developing on a diet of milkweed seeds, but that on a milkweed seed diet development took significantly longer.

Slater found that on Heliopsis helianthoides the mean development time from oviposition to the final molt to the adult stage was 41 days. Adult longevity in the laboratory was up to three months.

Slater attempted to cross breed the two species Lygaeus kalmii and L. turcicus and failed, thus putting to rest the notion that the two might represent the same species.

Slater's telling of this story points out the dangers of relying too much on literature and too little on one's own field observations. Slater said the moral of the story was "the importance of, and the need for, enthusiastic amateurs in American entomological study."

Photographer's note: As for me, I had never looked at the literature, and thus I was never aware of any confusion, or of the findings of Slater's informants. I found when I began insect photography that L. turcicus was invariably found sunflowers or other yellow composites. Near my West Virginia home I have found L. turcicus more common than L. kalmii, though both yellow composites and milkweeds abound.

Map, Lygaeus turcicus

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