Cryptachaea pacoti Brescovit, 2024

Araújo, Fláildo Da Silva, Brescovit, Antonio Domingos, Pereira, Luis Campili, Bonilla, German Antonio Villanueva- & Sobczak, Jober Fernando, 2025, Cryptachaea pacoti, a new species of spider from Brazil (Araneae: Theridiidae), with notes on parasitoid-host interaction under the influence of abiotic factors, Zootaxa 5642 (3), pp. 271-286 : 274-281

publication ID	https://doi.org/10.11646/zootaxa.5642.3.5
publication LSID	lsid:zoobank.org:pub:F9581FE2-BE2A-4E42-BD51-C596A71F6641
DOI	https://doi.org/10.5281/zenodo.15563827
persistent identifier	https://treatment.plazi.org/id/981187CF-F42C-FF8E-FF44-CF605747FF2D
treatment provided by	Plazi
scientific name	Cryptachaea pacoti Brescovit, 2024
status	sp. nov.

Treatment

Cryptachaea pacoti Brescovit, 2024 , new species

Figures 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5

Type material. Holotype: Male from Pacoti (4°13′30″S, 38°55′22″W), Ceará, Brazil, 20.i.2024, F.S. Araujo col., deposited in IBSP 345148 GoogleMaps . Paratypes: female with same data, 08.x.2023 ( IBSP 345158 View Materials ) GoogleMaps . Paratypes from Sítio São Luís , Pacoti (4°14'03.0"S 38°53'26.0"W), Ceará, 08.x.2023, F.S. Araújo. col., 1♀ ( IBSP 345167 View Materials ) GoogleMaps ; 1♂ ( IBSP 345161 View Materials ) ; 1♂ ( IBSP 345163 View Materials ) .

Other material examined. BRAZIL. Ceará: Pacoti (4°14'03.0"S 38°53'26.0"W), Sítio São Luís GoogleMaps , 08.x.2023, 1♀ ( IBSP 345145 View Materials ) ; 1♀ ( IBSP 345154 View Materials ) ; 1♀ ( IBSP 345155 View Materials ) ; 1♀ ( IBSP 345164 View Materials ) ; 28.x.2023, 1♀ ( IBSP 345146 View Materials ) ; 1♂ 1♀ ( IBSP 345147 View Materials ; SEM ♀) ; 1♀ ( IBSP 345149 View Materials ) ; 1♀ ( IBSP 345150 View Materials ) ; 1♀ ( IBSP 345151 View Materials ) ; 1♀ ( IBSP 345153 View Materials ) ; 1♀ ( IBSP 345157 View Materials ; Photo of Light coloring) ; 1♀ ( IBSP 345159 View Materials ; Photo of dark coloring) ; 1♀ ( IBSP 345156 View Materials ; Photo of intermediate coloring) ; 01/I/2024, 1♀ ( IBSP 345183 View Materials ) ; 20/I/2024, 1♂ ( IBSP 345143 View Materials ) ; 1♂ ( IBSP 345144 View Materials ) ; 1♂ ( IBSP 345166 View Materials ) ; 1♂ ( IBSP 345168 View Materials ) ; 1♂ ( IBSP 345169 View Materials ) ; 1♂ ( IBSP 345170 View Materials ) ; 1♂ ( IBSP 345171 View Materials ; male photo) ; 1♂ ( IBSP 345172 View Materials ) ; 1♂ ( IBSP 345173 View Materials ) ; 1♂ ( IBSP 345174 View Materials ) ; 1♂ ( IBSP 345175 View Materials ; SEM) ; 1♂ ( IBSP 345176 View Materials ) ; 1♂ ( IBSP 345177 View Materials ) ; 1♂ ( IBSP 345178 View Materials ) ; 1♂ ( IBSP 345179 View Materials ) ; 1♂ ( IBSP 345180 View Materials ) ; 1♂ ( IBSP 345181 View Materials ) ; 1♂ ( IBSP 345182 View Materials ) ; 1♂ ( IBSP 345184 View Materials ) ; 1♂ ( IBSP 345185 View Materials ), all collected by F.S. Araújo.

Etymology. The specific name is a noun in apposition taken from the type locality.

Diagnosis. Males and females of Cryptachaea pacoti sp. nov. differ from other species of the genus in that the male palp presents a wrinkled area distally from the cymbium ( Fig. 3E View FIGURE 3 , 5A View FIGURE 5 ) and copulatory ducts bordering the inner edge and almost as long as the spermathecae ( Fig. 5C View FIGURE 5 ). The species that most closely resembles them is Cryptachaea digitus , which presents a wrinkled area on the cymbium and conductor with an enlarged apex (see Buckup et al., 2006, fig. 1), but differs from this species in that the femur I is medially thickened ( Fig. 1B View FIGURE 1 ) and the embolus is enlarged ( Fig. 1C View FIGURE 1 ). The female also resembles C. digitus in having an anteriorly positioned copulatory opening and large spermathecae (see Buckup et al., 2006, figs. 2–3), but differs in having rounded copulatory openings and more elongated copulatory ducts, almost as long as the spermathecae ( Figs. 2D View FIGURE 2 ; 5B View FIGURE 5 ).

Description. Male (Holotype; IBSP 345148). Carapace dark gray, with black thoracic groove. Chelicerae orange, with two teeth in promargin ( Fig. 3A View FIGURE 3 ) and one tooth in retromargin. Labium and endites yellow. Sternum yellow, with gray borders. Legs orange, except thighs, trochanters and base of femora cream. Abdomen, dorsal view, gray, with black bands on the lateral and posterior edge, and dorsally with several scattered white guanine spots ( Fig. 1A View FIGURE 1 ). Ventrally black, with two white guanine spots on the posterior side. Abdomen oval, with very small stridulatory organs. AME slightly larger than the other eyes, separated from each other by its diameter, and closer to the ALE. PME separated from each other by almost its diameter, just like PME. ALE and PLE almost together. Measurements. Total length 2.2. Carapace: length 1.1, width (larger width) 0.9. Abdomen length 1.1, width 0.7, high 0.6. Legs, formula 1423, length I/II/III/IV: femora 1.8/1.1/0.7/1.4; patellae 0.5/0.4/0.3/0.4; tibiae 1.7/0.75/0.5/0.75; metatarsi 1.3/0.8/0.6/0.9; tarsi 0.6/0.45/0.5/0.4. Total legs length: 5.9/3.5/2.6/3.85. Palp ( Figs. 1C–D View FIGURE 1 ; 3C–F View FIGURE 3 ; 5A View FIGURE 5 ): tegulum enlarged, with short spermatic duct; elongated and hyaline conductor, close to the distal area of the embolus; rectangular embolus.

Female (IBSP 345158). Carapace dark gray, but can vary to light brown ( Fig. 2A–C View FIGURE 2 ), with a lighter posterior dorsal edge. Chelicerae orange, with two teeth in promargin ( Fig. 4A View FIGURE 4 ). Labium and endites yellowish gray. Sternum yellow with brown edges.Yellowish legs with gray distal area of the joints.Abdomen, dorsal view, varying from dark gray to light brown, but with medial-longitudinal-lateral cream band, with enlarged colulus ( Fig. 4D View FIGURE 4 ). Ventral view gray. Abdomen spherical, with stridulatory organs as in male. Eyes as in male, except ALE and PLE separated from each other by about two-thirds of an eye’s diameter. Epigynum ( Figs. 2D View FIGURE 2 , 4C View FIGURE 4 , 5B View FIGURE 5 _D): epigynal plate with concave lateral edges and slightly grooved posterior edge; parallel and short copulatory ducts, between the spermathecae; spermathecae globose; fertilization ducts short, originate at the internal base of the spermatheca. Measurements. Total length 2.6. Carapace: length 1.3, width (larger width) 1.8. Abdomen length 2.0, width 1.8, high 1.9. Legs, formula 1423, length I/II/III/IV: femora 2.1/1.1/0.75/1.8; patellae 0.6/0.5/0.4/0.5; tibiae 1.4/0.8/0.5/0.55; metatarsi 1.5/0.9/0.65/1.1; tarsi 0.75/0.5/0.5/0.55. Total legs length: 6.35/3.8/2.8/4.5.

Variation. Among females, at least three shades of color were observed on the abdomen ( Fig. 2A–C View FIGURE 2 ). Two colors are more common among populations, the dark form and the lighter one. Some specimens have intermediate coloring, but this is represented in only 20% of the specimens sampled. Males varied little in coloration, and the majority of specimens followed the dark pattern ( Fig. 1A View FIGURE 1 ). Measurements: males (n = 10) - total length 1.8–2.0; carapace 1–1.1; femur I 1.5–2.0; females (n = 10) - total length 2.8–3.3; carapace 1.2–1.45; femur I 1.6–2.2.

Geographic distribution. Known only of the type locality ( Fig. 6 View FIGURE 6 ).

Host-parasitoid interaction

Of the 1,240 Cryptachaea pacoti sp. nov. spiders inspected in the field, 149 were carrying immature stages of the Zatypota riverai wasp ( Figure 7A–D View FIGURE 7 ). The immature stages of the wasp were attached to the dorsal posterolateral (N=88) ( Figure 7B–C View FIGURE 7 ) and anterolateral part of the abdomen (N=61) ( Figure 7A View FIGURE 7 ). Of the total number of parasitized spiders found, 61 had wasp eggs attached to their abdomen; 35 had first-instar larvae (a characteristic observed by the absence of segmentations); 28 had second-instar larvae (where they already had apparent segmentations), and 25 spiders had third-instar larvae, a characteristic observed by the appearance of retractable dorsal tubercles that are defined in the final stage of larval development, when the spider is about to be killed. In the laboratory, the pupal stage lasted on average 10 days (maximum = 15; minimum = 7; N = 18). Additionally, we found 39 Z. riverai cocoons present on the leaf used as shelter by C. pacoti sp. nov. ( Figure 7E View FIGURE 7 ), which were also included in the parasitoidism rate.

Frequency of parasitoidism in wasp-spider interactions

The abundance of parasitized C. pacoti individuals did not vary significantly over the year (G test: G = 48.547; d.f. = 80; p = 0.97), ( Table 1 View TABLE 1 ). However, there is a peak of abundance between the months of April and May (Rayleigh’s test: z = 13.219; p <0.0001). Additionally, the frequency of parasitoidism also showed a marked peak between the months of March and May (Rayleigh’s test: z = 6.815; p = 0.001), with a mean parasitoidism percentage rate of 14.9% ± 4.5 ( Figure 8 View FIGURE 8 ).

Association of rainfall and temperature with parasitoidism

We detected a positive relationship between parasitoidism rate and rainfall (Pearson correlation: R = 0.69, p = 0.013) ( Fig. 9B View FIGURE 9 ) and no relationship between total spider abundance and precipitation (Pearson correlation: R = 0.25, p = 0.42, Fig. 9A View FIGURE 9 ). On the other hand, temperature was negatively related to both: total spider abundance (Pearson correlation: R = -0.69, p = 0.013) ( Fig. 9C View FIGURE 9 ) and parasitoidism rate (Pearson correlation: R = -0.57, p = 0.051) ( Fig. 9D View FIGURE 9 ).