Tequus schrottkyi (Konow 1906)

Altesor, Paula, Gonzalez, Andres & Schmidt, Stefan, 2016, First report of Tequusschrottkyi (Konow) (Hymenoptera: Pergidae) in Uruguay, and information about its host plant and biology, Biodiversity Data Journal 4, pp. 7538-7538 : 7538

Tequus schrottkyi (Konow 1906)

Tequus schrottkyi Acorduleceros Schrottkyi Konow 1906: 345-346. Type locality: Paraguay: Villa Encarnación. Lectotype female, designated by Smith 1980: 101. Type depository: Senckenberg Deutsches Entomologisches Institut, Müncheberg, Germany. Described: female.

Acordulecera schrottkyi : Smith 1978: 179.

Tequus schrottkyi : Smith 1990: 190.

Distribution

Paraguay, Uruguay

Ecology

In INIA - Las Brujas field station, T. schrottkyi larvae were only found feeding on S. commersonii in autumn and early winter between March and July. Solanum commersonii is a perennial plant that has its center of distribution in Uruguay, but also occurs in Paraguay, Brazil and Argentina ( Spooner and Hijmans 2001). Therefore, this plant may also be the host of T. schrottkyi in Paraguay, where it was originally reported. Since S. commersonii foliage is less available during spring and summer in this area, it is assumed that T. schrottkyi enters diapause and/or moves to another host plant during the rest of the year.

Between March and July T. schrottkyi presents several generations. Field temperature range measured during the sampling months was of 25 ± 4 °C (average maximum in March) and 5 ± 4 °C (average minimum in June) (mean ± SD) ( INIA-Uruguay 2015). Under controlled laboratory conditions (21 ± 3 °C, 50 ± 10 % RH, 14:10 L:D regime), larvae collected as first and second instars (Figs 2, 3) and maintained on S. commersonii feeding on the leaves successfully completed their larval stage in less than 5 days and the prepupal and pupal stage to adulthood in aproximately 9 days (P. Altesor, unpublished) (Fig. 4). Mature larvae form a silk cocoon in the soil in which they pupate (Fig. 5), with female pupae roughly twice as large as male pupae (20.4 ± 1.1 mg, N = 14 and males: 9.3 ± 0.5 mg, N = 12 (mean ± SEM).

Biology

Adults are sexually dimorphic, the female being larger than the male and with a different colour pattern. Compared to females, males have the thorax more extensively orange, and the abdomen black except more or less yellow orange laterally (in the female, the abdomen is orange except basally and apically more or less black) (Figs 6, 7, 8). Sexual dimorphism is common in the Pergidae , and often is expressed by differences in the antennal structure, color, and body size ( Schmidt and Smith 2006).

Females lay the eggs individually in the leaf margin, into the leaf tissues as is typical of Symphyta ( Smith 1990, Smith 1972, Weltz and Vilhelmsen 2014) (Fig. 9) (there are several eggs per leaf, but not clustered). In the laboratory, virgin females (24 - 48 h of age) laid eggs on S. commersonii , from which only male larvae emerged (arrhenotokous parthenogenesis).